用triazole修饰的Ru-carbene复合物:一个有效的olefin转化预催化剂,通过C=C键形成来实现动态共价化学
Chenhuan Wang1, Shuyao Zhang1, Teng Yuan1
1Department of Chemistry, University of South Florida, Tampa, FL, USA.
Chem catalysis
|October 24, 2023
概括
新的1,2,3-三协调碳复合物 (TA-Ru) 能够在高温下进行具有挑战性的烯基转化. 这些强大的催化剂保持活力,在关键反应中表现优于现有的鲁碳预催化剂.
科学领域:
- 有机金属化学 有机金属化学
- 催化剂是一种催化剂.
- 有机合成 有机合成
背景情况:
- 碳复合物是olefin转化过程中的重要催化剂.
- 现有的无N结合的催化剂由于cis/trans异构化而表现出有限的热稳定性.
- 这种不稳定性降低了催化活性,特别是在苛刻的转换过程中.
研究的目的:
- 引入一类新型的1,2,3-三协调碳复合物 (TA-Ru).
- 为了证明这些新的TA-Ru催化剂的增强热稳定性和反应性.
- 探索它们在具有挑战性的氨酸转化反应中的应用.
主要方法:
- 新型1,2,3-三协调碳复合物的合成和表征.
- 在高温下 (高达80°C) 评估催化剂的稳定性.
- TA-Ru催化剂在交叉转移 (CM),环闭转移 (RCM) 和动态共价化学 (DCvC) 的应用.
主要成果:
- TA-Ru复合物表现出前所未有的热稳定性,在80°C保持活跃的跨二形状.
- 在具有挑战性的基板上实现了有效的烯转化.
- TA-Ru催化剂的反应性超过了Grubbs II和Hoveyda-Grubbs预催化剂的反应性.
结论:
- 1,2,3-三醇协调的鲁碳复合物代表了一代新一代强大的烯转化催化剂.
- 与以前的N-协调系统相比,TA-Ru催化剂提供了更好的性能和热稳定性.
- 这种催化系统为复杂的有机合成提供了转化方法.
相关概念视频
01:13Olefin Metathesis Polymerization: Overview
2.1K
Recently, the development of olefin metathesis polymerization advanced the field of polymer synthesis. Simply put, the reorganization of substituents on their double bonds between two olefins in the presence of a catalyst is known as the olefin metathesis reaction. The use of metathesis reaction for polymer synthesis is called olefin metathesis polymerization.
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists...
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists...
2.1K
01:16Cycloaddition Reactions: MO Requirements for Thermal Activation
3.6K
Thermal cycloadditions are reactions where the source of activation energy needed to initiate the reaction is provided in the form of heat. A typical example of a thermally-allowed cycloaddition is the Diels–Alder reaction, which is a [4 + 2] cycloaddition. In contrast, a [2 + 2] cycloaddition is thermally forbidden.
3.6K
01:12Cycloaddition Reactions: MO Requirements for Photochemical Activation
2.1K
Some cycloaddition reactions are activated by heat, while others are initiated by light. For example, a [2 + 2] cycloaddition between two ethylene molecules occurs only in the presence of light. It is photochemically allowed but thermally forbidden.
2.1K
01:16Olefin Metathesis Polymerization: Ring-Opening Metathesis Polymerization (ROMP)
2.6K
Ring-opening metathesis polymerization or ROMP involves strained cycloalkenes as starting materials. The mechanism of ROMP proceeds by reacting cycloalkene with Grubbs catalyst to give metallacyclobutane intermediate which undergoes a ring-opening reaction to form new carbene. The new carbene reacts with another molecule of cycloalkene. Repetition of these steps leads to the formation of an unsaturated open-chain polymer product. All these steps are reversible, however, relieving the ring...
2.6K
00:53Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)
1.9K
Acyclic diene metathesis polymerization or ADMET polymerization involves cross-metathesis of terminal dienes, such as 1,8-nonadiene, to give linear unsaturated polymer and ethylene. As ADMET is a reversible process, the formed ethylene gas must be removed from the reaction mixture to complete the polymerization process.
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
1.9K
01:33Carboxylic Acids to Methylesters: Alkylation using Diazomethane
2.2K
Carboxylic acids react with diazomethane in an ether solvent via alkylation at the carboxylate oxygen atom to give methyl esters of the corresponding acid with excellent yields.
2.2K